Charlie Waller was the constant gentleman, not just as the only career-long member of the Country Gentlemen, the seminal bluegrass band he helped found almost a half-century ago, but also as the embodiment of creative consistency. When Waller gave his final local performance at the Birchmere on July 26, his smooth, powerful tenor was as unmistakable as ever, his enunciation natural and easy, with every syllable clear and beautiful. Some have suggested that had Waller chosen country music over bluegrass, he'd now be talked about in the same breath as George Jones.

But Waller, who died Wednesday in Gordonsville, Va., at age 69, was a bluegrass thoroughbred, one of the genre's most important second-generation figures. The Country Gentlemen helped popularize bluegrass in the late '50s and early '60s in ways that even an originator such as Bill Monroe could not. The classic 1959 lineup -- Waller on guitar, mandolinist-singer John Duffey, bassist Tom Gray and banjo player Eddie Adcock -- did it with a startlingly fresh approach. They played with a near-jazz feel, and Waller's voice was strong, deep and distinctive, without the nasal quality of his predecessors.

In addition, the Country Gentlemen's repertoire broke the mold of bluegrass tradition, borrowing heavily from folk, rock and popular tunes of the day, while the hilarious stage antics of Duffey and Adcock offered an alternative to the grim-faced, tight-lipped style of most bluegrass bands. As a result, the Country Gentlemen would become the most influential bluegrass act since Monroe, the first to attract a broad audience not open to more traditional bands.

According to Eddie Stubbs, announcer for the Grand Old Opry and a former member of the Maryland-based Johnson Mountain Boys, the Country Gentlemen "had a unique stage presentation, a great form of entertaining audiences and a way of appealing to urban audiences that some of the first-generation bands did not have. . . . It's hard to imagine the Country Gentlemen coming to an end, considering their importance to the music and the musical culture as well, not just in bluegrass overall but in the history of Washington music overall."

Washington might never have enjoyed its shining reputation as the bluegrass capital of America in the '60s without Charlie Waller and the Country Gentlemen. Born in Texas and raised in Louisiana, Waller moved here in 1945 at age 10 to join his mother, who had come to work for Pepco. By 13, his guitar skills were advanced enough for him to start playing in local beer joints. When his voice deepened and he added vocals to his arsenal, Waller sounded very much like his country idols, Hank Snow and Mac Wiseman.

In the '50s Waller played in bars here and in Baltimore; starting in 1955, he played off and on with popular mandolinist Buzz Busby and his Bayou Boys. Busby's band, which also featured banjo player Bill Emerson and guitarist Adcock, had a regular gig at the Admiral Grill at Baileys Crossroads. But several members of the band were involved in a car accident early in July 1957 on the way home from a job in Calvert County. Busby was seriously injured and Adcock was hospitalized.

Hoping to keep the Admiral Grill job, Emerson drafted Waller and a friend, a young mandolin player and tenor singer named John Duffey. On July 4, 1957, what would soon be the Country Gentlemen played their first date, liked what they heard and decided to strike out on their own. Duffey, the son of an opera singer, came up with the name, noting that a lot of bluegrass bands were calling themselves the so-and-so Mountain Boys. "We're not mountain boys," Duffey noted of his mostly urban-bred band mates. "We're gentlemen."

Within months, the Country Gentlemen had become local sensations with such early classics as "Matterhorn," "Legend of the Rebel Soldier," "Long Black Veil," "Dark as a Dungeon" and "Fox on the Run." Georgetown's Shamrock, a rowdy bar on M Street (now Winston's), became the center of an urban bluegrass boom, thanks to the Gentlemen's residency there from 1960 to 1972.

From the start, the group proved musically progressive, exploring contemporary country, rock and singer-songwriter material (they were the first bluegrass band to cover Bob Dylan). They were never afraid to stretch limits, making bluegrass up-to-date without abandoning its deep-rooted style. For this, the Gents were criticized by purists for playing what was dismissively dubbed "newgrass."

But the Country Gentlemen's accessible approach quickly made them the music's most successful ambassadors.

"We may have offended some of the die-hards," Waller told me in 1982, when the band celebrated its 25th anniversary, "but basically we did tasteful stuff, and me being really more of a country singer added another flavor to bluegrass. We made an awful lot of people come over."

Along with Flatt & Scruggs -- a duo introduced to mass audiences by "The Beverly Hillbillies" theme song -- the Country Gentlemen probably inspired more bluegrass converts in the '60s than Bill Monroe himself. What came to be known as the "classic" Country Gentlemen lineup -- the first modern group inducted into the International Bluegrass Music Association Hall of Honor -- took form in 1959 featuring Waller on low tenor, Duffey on high tenor and Adcock on baritone. The Country Gentlemen recorded with many labels, but it was with Rebel Records that they became stars, starting with 1965's classic modern-day ghost fable, "Bringing Mary Home" (their only chart hit).

Over the decades, Charlie Waller served much the same role as drummer Art Blakey did with his Jazz Messengers, leading a constantly touring ensemble whose lineup was ever-changing but whose sound pretty much stayed the same. There have been more than 100 Gentlemen, including Ricky Skaggs, Jerry Douglas, Doyle Lawson and of course John Duffey, who quit in 1969 because he was tired of touring and opened an instrument repair business in Arlington. Two years later Duffey was lured into playing a local "pickin' party" with other area musicians, and it sounded so good they decided to put a group together -- the Seldom Scene. In the '70s, the Scene took the sound invented by the Country Gentlemen and eventually surpassed them in impact and popularity.

But Waller kept his band going, serving as its steward and anchor, though it wasn't until 1993 that it started being called Charlie Waller and the Country Gentlemen. He had some serious health problems and in 2000 suffered a minor stroke. Waller sometimes was stiff and tired-looking onstage, but his voice never seemed to diminish.

Pete Kuykendall, an ex-Country Gentleman and founder of Bluegrass Unlimited magazine, the bible of the genre, saw Waller perform just a few months ago. "His voice even seemed to improve with age, with that great timbre," he recalls. "He sounded fabulous, every bit as good as when I first heard him," which was more than 50 years ago. Now, the longest-operating band in bluegrass has been silenced by the passing of its voice and heart.

Bluegrass thoroughbred: Charlie Waller on tour with the Country Gentlemen in 1982.In 1982, the Gentlemen consisted of the ever-present Waller, left, Bill Yates, Dick Smith and Jimmy Gaudreau, sitting.